The present invention relates to a method and an apparatus for determining a sensor signal.
Electric and hybrid vehicles are becoming increasingly important. Regulation of permanently excited synchronous machines (PSM) and electrically excited synchronous machines (ESM), as are used in such vehicles, requires knowledge of the rotor angle of such machines. In addition, regulation of asynchronous machines (ASM) requires knowledge of the electrical frequency of the drive. The rotor angle and the electrical frequency can be ascertained using different types of sensor. For example, sensors based on the Eddy current effect, resolvers or digital angle sensors are possible.
A resolver is excited in this case using a preferably sinusoidal carrier signal, for example. The receiver signals obtained from the resolver in this case are normally perturbed, amplitude-modulated voltages from whose envelope it is possible to obtain the information about the rotor position.
The German patent application DE 10 2011 078 583 A1 discloses evaluation of resolver signals in a vehicle, for example. To this end, a resolver picks up a rotary movement of a rotor, and a processor element processes the sinusoidal and cosinusoidal output signals of the resolver.
There is a need for reliable determination of a sensor signal. In particular, there is a need for reliable determination of a rotor angle, for example, even for a perturbed output signal of a sensor.